I sent BTC/ETH to the wrong address, can I get them back?

When sending cryptoassets to another wallet, a right of ownership of a unit of said cryptoasset is transferred to another wallet. It is absolutely impossible for us to access these cryptoassets again, if an error has been made with the receiving address, because we no longer hold these crytpoassets. Therefore, there is technically no way to recover the funds in question unless you know who owns the receiving address and make a request to return the funds.

Similarly, it is absolutely impossible to recover cryptoassets that have been sent to a receiving address corresponding to a different cryptoasset.